TENTZHEN
A Chinatown street at night, seen from the sidewalk, between brick buildings. Tents line the dark, shut shops on one side, glowing from inside; the nearest, its door open, is kept as a home, with a made bed, books, a laptop on a crate and fairy lights; across the street the shops are open and lit. A copper trace inlaid in the sidewalk leaves its door and joins a path that runs from your feet straight down the street, under a gate and past red sign boards and lanterns, to the door of the tallest tower in a lit skyline.

Build your own safety net.

Cheap electronics and free tools are everywhere. Learn to measure, fix and build with them.

The Tentzhen mark: a peregrine falcon beside 腾振, drawn as circuit-board traces

A bench you can set up anywhere, stocked from the world's electronics surplus.

An attempt to build the whole bench — scope, signal generator, supply and load — from generic parts, and to publish every step so others can follow.

Read the plan Source on GitHub
U1

Instrument #1

A two-channel digitizer and signal generator in the Red Pitaya class.

FPGA
Colorlight i9 · Lattice ECP5 LFE5U-45F
ADC
2× AD9226 modules · 12-bit · up to 65 MS/s
SOC
LiteX + VexRiscv · firmware in Rust
AFE
Custom analog front end · KiCad, fabricated at JLCPCB
HOST
Rust services: DuckDB ingest, SCPI, MCP
RED PITAYA 125-14TENTZHEN #1 TARGET
Channels in / out2 / 22 / 2, outputs in phase 5
Sample rate125 MS/sup to 65 MS/s
Resolution14-bit12-bit
BandwidthDC–60 MHz20–30 MHz usable

unknownEvery Tentzhen figure is a target until it is measured.